1. Field of the Disclosure
The present inventions relate to a power transmitting apparatus for transmitting or cutting-off a rotational power of the input member to or from the output member.
2. Description of the Related Art
In general, power transmission apparatuses for vehicles such as motorcycles are designed to transmit and cut-off a power of an engine to a transmission and a driving wheel. Such power transmission apparatus typically include an input member connected to an engine-side, an output member connected to the transmission and the driving wheel-side, and a clutch member connected to the output member. Power can be transmitted by pressure-contacting a plurality of driving clutch plates with a plurality of driven clutch plates and can be cut-off by releasing the pressure-contacting force between the driving clutch plates and driven clutch plates.
Some known power transmitting apparatuses include a clutch housing rotatable together with an input member and a plurality of driving clutch plates mounted thereon. The power transmitting apparatus further comprises a plurality of driven clutch plates alternately arranged between the driving clutch plates of the clutch housing, a clutch member connected to an output member, a pressure member mounted on the clutch member and axially movable relative to the clutch member for carrying out the pressure-contact and release between the driving clutch plates and the driven clutch plates with its axial movement relative to the clutch member, and an intermediate member spline-fitted thereon with the driven clutch plates. This type of power transmitting apparatus is constructed so that a rotational power inputted to the input member may be transmitted or cut-off to or from the output member by performing pressure-contact or release between the driving clutch plates and the driven clutch plates.
Additionally, some power transmitting apparatuses include back-torque limiting cams. Such back torque limiting cams typically comprise clutch member-side cam surfaces formed on the clutch member and intermediate member-side cam surfaces formed on the intermediate member. The back torque cams are adapted to axially move the pressure member and the clutch member by the cam action between the clutch member-side cam surfaces and the intermediate member-side cam surfaces in order to release the pressure-contact between the driving clutch plates and the driven clutch plates when the rotational speed of the output member has exceeded that of the input member and a relative rotation between the pressure member as well as the intermediate member and the clutch member has been caused (see e.g. Japanese Laid-open Patent Publication No. 96222/1986 and Japanese Laid-open Patent Publication No. 149618/1986).